A sexual act whereby the male/female decides to unload both the solid and liquid forms of waste from themselves onto thier partner, at the same time, thus giving the same effect as a traditional "Bog-Wash".
Oliver: You'd have sex with that beast of a girl Claire?!, i'd rather take a bog-washin' off Vanessa Feltz!
Sticking your head in the bog (toilet) and flushing the chain. Apparently also known as a 'swirlie' in other parts of the world.
Occurs mainly in school and administered by bullies.